1. Field of the Invention
The present invention generally relates to the forming of inductive elements by using integrated circuit and printed circuit manufacturing technologies. The present invention more specifically relates to the forming of planar inductive windings.
2. Discussion of the Related Art
A planar inductive winding is formed by a spiral-shaped conductive track in a conductive level of an integrated circuit or of a printed circuit. Most often, the spiral structure is, in the plane, surrounded with a surface intended to be connected to ground (the ground plane). According to applications, several spiral windings may be interdigited in a same plane and several windings or pairs of windings may be superposed in different conductive levels to form coupled structures.
A problem which is made more and more critical by miniaturization needs is a significant temperature rise at the center of the spiral structure. This temperature rise may result in a deterioration of the structure or require an increase in the width of the conductive track, which goes against the desired miniaturization.